The Walrus or Odobenidae family used to be fairly diverse, being made up of over twenty species which were divided into several sub-families. Sadly, today the Walrus (Odobenus Rosmarus) is the sole surviving member. Environmental changes, global warming and loss of habitat are major concerns while oil spills, entanglement and chemical pollutants such as DDT and PCB are also affecting them. These animals may stampede if disturbed, squashing any pups in the process and breeding haul-outs have been known to become completely abandoned due to human interference. They were hunted extensively by commercial sealers and are listed on both Appendix III of CITES as well as Appendix II of the Bern Convention.
During the mating season, which runs from January through to April, adult males will attract females by emitting a number of knocking or tapping sounds while under water. Mating takes place in the water and fights and skirmishes between adult males are frequent.
The gestation period last around 15 months with older females only reproducing every 3rd or 4th year. This pregnancy rate is the lowest of all pinnipeds and makes the species even more vulnerable from indiscriminate hunting. Pups are born with a thick black coat and measure 1.2m long and weigh in at between 50 and 60kg at birth. Adult males can weigh up to 1400kg. Sexual maturity in females is reached at between 4 and 10 years
Pups will feed solely on a diet of high fat content milk for their first 6 months before moving on to solids. The entire weaning process takes around two years.
During summer, males and females tend to separate and will feed in different areas. This seasonal segregation is particularly apparent with walruses living in the Pacific. During the breeding season, almost all of them can be found in the Bering Sea. As the ice melts, females and juveniles tend to move northwards, following the melting ice, while the bulls tend to remain in the area.
The walruses tusks are in fact over-sized upper canines. They can grow to over 1m in length and weigh about 5kg. Not only are these tusks used for fighting and threat displays, but the walrus will also use them to haul itself onto the ice. In fact, its Latin name means “tooth-walking horse.” These tusks are made of solid ivory. A demand for carved walrus tusks has led to the problem of “head hunting” by syndicates operating the drugs and illegal ivory trade. In 1996, over 160 headless walruses washed up on the beaches of Alaska.
Walrus meat has been used as a source of food on government subsidized fox fur farms in Chukotka, Russia for the last 50 years.
When BP executives stood before congress to explain their oil spill emergency plan for the Gulf of Mexico, they mentioned protecting the Walrus was one of their top priorities. Walruses have not called the Gulf home for at least the last 3 million years.
Their “whiskers” are not in actual fact hairs. Rather these ‘vibrissae’ are a type of tactile organ which is used to help them find food when diving. A single dive can last over 30 minutes, during which they can consume as many as 6 000 clams or around 5% of their body weight each day.
Walruses swim at a cruising speed of around 8km/hr but can manage short bursts of over 30km/hr. The oldest walrus on record lived to well over 40 but mostly they live to around 30 years.
The earliest recorded Walrus in captivity was in 1608.